A new step toward environmentally friendly electricity has been made through the discovery of a new alloy material that converts heat into electricity directly. 

Richard James, study leader and University of Minnesota aerospace engineering and mechanics professor, along with University of Minnesota aerospace engineering and mechanics post-doctoral researchers Vijay Srivastava, Kanwal Bhatti and Ph.D. student Yintao Song, have used a new alloy to create electricity from heat. This could eventually lead to capturing waste heat from car exhaust and using it to create electricity for a hybrid car battery, thus recycling energy.

The material was created through the combination of elements at the atomic level. This led to the development of a new multiferroic alloy called Ni₄₅Co₅Mn₄₀Sn₁₀. This alloy underwent a "highly reversible" phase transformation where a solid turns into another solid, and during this transformation, its magnetic properties changed. These changes show in the energy conversion instrument. The material starts out as non-magnetic, and then becomes increasingly magnetic as the temperature increases. The material absorbs the heat and produces electricity in a coil.

Some of the recovered heat is lost through the process hysteresis, but the University of Minnesota team found a way to reduce this process and absorb more heat. 

"This research is very promising because it presents an entirely new method for energy conversion that's never been done before," said James. "It's also the ultimate 'green' way to create electricity because it uses waste heat to create electricity with no carbon dioxide." 

The team is also working on making a thin film of the material to convert heat from computers into electricity. 

"This research crosses all boundaries of science and engineering," said James. "It includes engineering, physics, materials, chemistry, mathematics and more. It has required all of us within the university's College of Science and Engineering to work together to think in new ways."

This study was published in Advanced Energy Materials.